The term “dietary supplement” defines a comprehensive and diverse category of products that are essential to our health but are absent or insufficient in the diet and may be needed to take separately; requirement of dietary supplements varies at different stages of life, such as infant, child-adult, pregnancy, lactation, and geriatrics. Dietary supplements are not medicines, nor should they be considered a substitute for food. The USFDA defines dietary supplements in part as a product taken by mouth that contains “dietary ingredients.” Nutritional ingredients comprise vitamins, minerals, amino acids, and herbs or botanicals, in addition to other substances that can be considered to supplement the diet. The market is flooded with various dosage forms of dietary supplements, such as capsules, tablets, powders, energy bars, liquids, etc. These include vitamins, minerals, herbal products containing extracts from herbs as well as algae and fungi, concentrate, metabolite, constituent, or extract, enzyme supplement, essential amino, and fatty acids. This article describes the importance of the dietary supplement, source, diseases that arise by deficiency, and the recommended doses for different groups.